Evaluation of the Storage Characteristics in Maintaining the Overall Quality of Whole and Fresh-Cut Romaine Lettuce during MA Storage

In-Lee Choi,Joo-Hwan Lee,Li-Xia Wang,Dam-Hee Choi,Ho-Min Kang

doi:10.3390/horticulturae7110461

In-Lee Choi, Joo-Hwan Lee + Show 3 more

Open Access

https://doi.org/10.3390/horticulturae7110461

Copy DOI

Abstract

This study aimed to examine the effect of modified atmosphere (MA) storage on the quality and storability of romaine lettuce. Whole and fresh-cut romaine lettuce were packaged with 1300; 10,000; 50,000; 100,000 cc m−2·day−1·atm−1 O2 transmission rate (OTR) films and stored at 2 or 8 °C for 15 days. The respiration and ethylene production rates before pre-cooling were higher in fresh-cut lettuce than in whole romaine lettuce. The reduction in fresh weight for whole and fresh-cut romaine lettuce during storage was less than 0.5%. The CO2 concentration was less than 2%, except for the 1300 cc treatment (at 8 °C for whole and fresh-cut lettuce) and 10,000 cc (in fresh-cut lettuce). At the end date of storage, the overall quality of the whole lettuce was good, the off-odor was lower in the 10,000 cc treatment, and the 50,000 cc treatment at 8 °C led to good overall quality in the fresh-cut lettuce. The chlorophyll content of the whole lettuce was maintained at a higher level in the treatment of 10,000 cc at 8 °C, while it was higher in the 50,000 cc treatments at 2 and 8 °C in the fresh-cut lettuce. Correlation and PCA confirmed that the main factors affecting the storability and quality of romaine lettuce were fresh weight loss rate, off-odor, and the concentration of CO2. In addition, the storage characteristics of whole and fresh-cut lettuce were opposite to 0 in PC1 and PC2, indicating that the storage characteristics were different depending on the processing type.

Highlights

Romaine lettuce is a crop cultivated year round, and the market size is gradually increasing according to consumer demand for fresh-cut lettuce
The findings are similar to Kays and Paull [24] and Cantwell and Suslow [2], who reported that the ethylene production rate of romaine lettuce was very low, less than 0.02 C2 H4 μL·kg−1 ·h−1
PC1 and PC2 of the whole and fresh-cut lettuce were loc opposite of the zero point, indicating that the effects of the storage characteristics on storage properties were different depending on the processing type, even for the s crop (Figure 6A,B)

Summary

Introduction

Romaine lettuce is a crop cultivated year round, and the market size is gradually increasing according to consumer demand for fresh-cut lettuce. In the case of fresh-cut agricultural products, they are prone to secondary quality degradation, which speeds up browning or microbial growth due to the respiration caused by cutting after harvest and the rapid increase in ethylene [1,2]. Studies on romaine lettuce have focused on topics such as cultivation [3,4], the quality of baby leaves [5,6], and comparisons of freshness maintenance according to packaging type for each type of lettuce [7]. Studies on fresh-cut romaine lettuce have focused on the inhibition of browning caused by cutting [3,8] and on storability [9,10]. In the case of loose-leaf lettuce, it has been reported that in low storage temperatures, inherent factors, such as variety, are suppressed, resulting in no difference in storability, and the extent of this reduction increases depending on the permeability when stored in PP films [6,11]

Objectives

Methods

Results

Conclusion